1. he owns a very expensive house. he must be a rich person. 2. i could swim well when i was a child. i even won the school championships. 3. you needn't go to the grocery store. we have some milk in the fridge. 4. i couldn't find my keys. i probably left them at my mother’s place. 5. you mustn't buy the tickets. i got two for free from dad. 6. she didn't need speak so rudely to her parents. 7. the teacher always tells us we mustn't cheat during a test. 8. i couldn't stop laughing. the joke was so funny. 9. i can't look at you. you’re so dirty. what were you up to? 10. can you turn down the volume? – it’s too loud.
Environmental problems have become one of the most urgent problems of modern society. more and more people suffer from air and water pollution. nature also suffers from land and nuclear pollution. the reasons for such environmental problems are numerous. among them increasing number of cars in the streets, factory waste, millions of cut down trees, destroyed habitats of animals, contaminated rivers and seas. all these problems mainly arise due to human careless activities and gradually destroy our planet. if we look closely, we’ll notice that not only one city is under danger, but the majority of world population.
